Db. Thordarson et al., RECONSTRUCTION WITH TENODESIS IN AN ADULT FLATFOOT MODEL - A BIOMECHANICAL EVALUATION OF 4 METHODS, Journal of bone and joint surgery. American volume, 77(10), 1995, pp. 1557-1564
Six fresh-frozen adult cadaveric specimens were mounted in an Instron
materials testing machine with nse of a cemented intramedullary rod, A
ngular relationships between the first metatarsal and the talus were r
ecorded with a sonic digitizer, A flatfoot deformity was created by di
viding the talonavicular joint capsule (superiorly, medially, and infe
riorly), the spring ligament, the anteromedial aspect of the subtalar
joint capsule, and the plantar fascia, Angular displacement in the sag
ittal and transverse planes was recorded at no load and at 100, 350, a
nd 700-newton plantar loads, Each specimen was subjected to four diffe
rent reconstructions with tenodesis, and the angular relationship betw
een the first metatarsal and the talus was measured at the four levels
of load, A reconstruction with use of the peroneus longus tendon was
performed by preserving its insertion into the first metatarsal, rerou
ting the tendon and passing it from medial to lateral through a calcan
eal bone tunnel, and anchoring it to the lateral aspect of the calcane
us, A reconstruction with the tibialis anterior tendon was performed b
y passing the medial third of the tendon from dorsal to plantar throug
h the navicular and from medial to lateral through the calcaneal bone
tunnel and securing it to the lateral aspect of the calcaneus, The rec
onstruction with the tibialis anterior tendon was repeated with the te
ndon graft routed along the medial aspect of the navicular, directly t
hrough the calcaneal bone tunnel, The fourth reconstruction was done w
ith use of an Achilles tendon allograft, For this procedure, a bone pl
ug was secured, with an interference screw, in the medial aspect of th
e calcaneal bone tunnel, and the graft was passed from plantar to dors
al through the navicular and sewn to itself,The reconstruction,vith th
e peroneus longus tendon provided significantly greater correction of
the deformity in both the transverse and the sagittal plane at all lev
els of load (p < 0.05), except the 700-newton load in the transverse p
lane, All reconstructions corrected, at least partially, the deformity
at both no load and the 100-newton load. CLINICAL RELEVANCE: The meth
ods that are used for reconstruction of a ruptured tibialis posterior
tendon do not correct the acquired flatfoot deformity of this conditio
n, A supple deformity without osseous deformity should be amenable to
soft-tissue reconstruction, Of the four methods that we evaluated for
reconstruction of a flatfoot deformity, the one involving use of the p
eroneus longus provided the best correction in both the transverse and
the sagittal plane, We believe that it has the greatest potential for
success in a clinical situation.